Fix broken CI due to broken macOS tests

CHANGES.rst

@@ -1,3 +1,14 @@
+v23.3.0
+-------
+
+* #529: macOS backend is no longer viable if the API module
+  cannot be loaded. Prevents "symbol not found" errors on
+  macOS 11 (Big Sur) and later when a "universal2" binary
+  is not used (available for Python 3.8.7 and later).
+
+* #547: Tests no longer attempt to run macOS backends even
+  on macOS when the backend is non-viable.
+
 v23.2.2
 -------
 

README.rst

@@ -54,6 +54,13 @@ install dbus-python as a system package.
 
 .. _dbus-python: https://gitlab.freedesktop.org/dbus/dbus-python
 
+Compatibility - macOS
+=====================
+
+macOS keychain support macOS 11 (Big Sur) and later requires Python 3.8.7
+or later with the "universal2" binary. See
+`#525 <https://github.com/jaraco/keyring/issues/525>`_ for details.
+
 Using Keyring
 =============
 

conftest.py

@@ -1,8 +1,23 @@
-import platform
+import ctypes
 
 collect_ignore = ["hook-keyring.backend.py"]
 
-if platform.system() != 'Darwin':
-    collect_ignore.append('keyring/backends/macOS/api.py')
+
+def macos_api_ignore():
+    """
+    Starting with macOS 11, the security API becomes
+    non-viable except on universal2 binaries.
+
+    Ref #525.
+    """
+
+    try:
+        ctypes.CDLL(ctypes.util.find_library('Security')).SecItemAdd
+        return False
+    except Exception:
+        return True
+
+
+collect_ignore.extend(['keyring/backends/macOS/api.py'] * macos_api_ignore())
 
 collect_ignore.append('keyring/devpi_client.py')

keyring/backends/macOS/__init__.py

@@ -28,6 +28,8 @@ def priority(cls):
         """
         if platform.system() != 'Darwin':
             raise RuntimeError("macOS required")
+        if 'api' not in globals():
+            raise RuntimeError("Security API unavailable")
         return 5
 
     def set_password(self, service, username, password):

tests/backends/test_macOS.py

@@ -1,16 +1,14 @@
-import sys
-
 import pytest
 
+import keyring
 from keyring.testing.backend import BackendBasicTests
 from keyring.backends import macOS
 
 
-def is_osx_keychain_supported():
-    return sys.platform in ('mac', 'darwin')
-
-
-@pytest.mark.skipif(not is_osx_keychain_supported(), reason="Needs macOS")
-class TestOSXKeychain(BackendBasicTests):
+@pytest.mark.skipif(
+    not keyring.backends.macOS.Keyring.viable,
+    reason="macOS backend not viable",
+)
+class Test_macOSKeychain(BackendBasicTests):
     def init_keyring(self):
         return macOS.Keyring()